• Journal of Korean Society for Atmospheric Environment
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• v.4 no.2
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• pp.67-71
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• 1988

To estimate the probability of short term concentration of air pollution using long term arithmetic average concentration, the procedure was developed and added to Texas Climatological Model version 2. In the procedure, such statistical characteristics that frequency distribution of short term concentration may be approximated by a lognormal distribution, were applied. This procedure is capable of estimating not only highest concentration for a variety of averaging times but also concentrations for arbitrary occurrence frequency. Evaluation of the procedure with the results of short term concentrations calculated by Texas Episodic Model version 8 using the meteorological data and emission data in Seoul shows that the procedure estimates concentrations fairly well for wide range of percentiles.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.9-20
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• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.69-78
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• 2018

This The purpose of this study is to find policy implications through the analysis of the operational cases and establishment performance of the Leading University for startups. The method of the study was statistical analysis using the data generated during the operation of the Leading University for startups. The results of the study show that there is a difference between short-term performance by gender and age. Second, there was no correlation of the short-term performance with the evaluation, but a negative correlation was observed with the detailed document evaluation part. Third, there is no difference in short-term performance depending on the mentor. Strategic utilization is to reduce the reflection of the founder's short-term performance in the appraisal of the Leading Universities. And there is a need to improve the evaluation method for the applicant. The limitations of this study are that it is inadequate to be an empirical study through statistical analysis. And statistical analysis shows that there are not enough cases. Therefore, I will make an empirical study which will expand the number of cases by including cases of several universities in the future.

• Proceedings of The Korean Cleft Lip And Palate Association
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• 2004.06a
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• pp.26-28
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• 2004

• 대한치주과학회:학술대회논문집
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• 1999.11a
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• pp.106-106
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• 1999

• 대한치과교정학회:학술대회논문집
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• 1999.11a
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• pp.34-36
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.361.2-361.2
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• 2003

• Journal of Technology Innovation
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• v.21 no.1
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• pp.331-364
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• 2013

This work aims firstly to analyse the evaluation expertise in the National IT Industry Promotion Agency(NIPA) which is charge of funding and promoting R&D programs in the field of IT industry, a main part of 'Technology Innovation Program for Knowledge Economy' supported by the Ministry of Knowledge Economy. It will also discuss the policy means for improvement of the evaluation expertise of the NIPA. The results show that the evaluation system of the NIPA has been fair in stage of the selection of evaluators and the career management system of evaluators. But it will be necessary for improvement in stage of the surroundings supporting the expertise during evaluation practise. Therefore, in order to improve the evaluation expertise of the NIPA, I suggested and discussed 12 policy means in accordance with the short term perspective and long term one.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.541-548
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• 2017

An increasing concern is paid to short-term voltage stability with the growth of penetration of induction motor loads. Reactive power reserve(RPR) of power system is critical to improve voltage stability. A definition of short-term voltage stability-related RPR(SVRPR) is proposed. Generators vary their contributions to voltage stability with their location and system condition, etc. Voltage support coefficient based on the second-order trace sensitivity method is proposed to evaluate SVRPR's contribution to short-term voltage stability. The evaluation method can account for the generator's reactive support in transient process and the contingency severity. Then an optimization model to improve short-term voltage stability is built. To deal with multiple contingencies, contingency weight taking into account both its probability and severity is proposed. The optimization problem is solved by primal dual interior point method. Testing on IEEE_39 bus system, it is indicated that the method proposed is effective. Short-term voltage stability is improved significantly by the way of SVRPR optimization. Hence, the approach can be used to prevent the happening of voltage collapse during system's contingency.

• Geotechnical Engineering
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• v.14 no.6
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• pp.127-138
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• 1998

In refuse landfills, a considerable amount of settlement occurs due to the decomposition of refuse over several years. In this paper, several prediction methods are applied to the measured settlement data of fresh refuse sites. The effect of biological decomposition on the settlement characteristics is investigated in predicting the long-term settlement of refuse landfill sites in view of the predicted settlement curves and the amount of long-term settlement. Irrespective of the applied models, the long term settlement may not be correctly estimated if the model parameters do not contain the decomposition effects. Among the proposed several prediction methods, Gibson & Lo model and hyperbolic model seem to represent the long-term settlement characteristics, but the power creep law seems to considerably overestimate the long-term settlement.